fixing PR_NUMBER evaluation when there is no opnfv-tht-pr in the commit message

Change-Id: I5abd9efe48a665f7a65201ec20805cd1a4001763
Signed-off-by: Dan Radez <dradez@redhat.com>

diff --git a/build/undercloud.sh b/build/undercloud.sh
index ca75bb0..3ac46e0 100755 (executable)
--- a/build/undercloud.sh
+++ b/build/undercloud.sh
@@ -31,10 +31,14 @@ LIBGUESTFS_BACKEND=direct virt-customize \
     -a undercloud.qcow2
 
 # Use apex tripleo-heat-templates fork
-PR_NUMBER=$(git log -1 | grep 'opnfv-tht-pr:' | grep -o '[0-9]*')
+PR_NUMBER=""
 REF="stable/colorado"
 REPO="https://github.com/trozet/opnfv-tht"
 
+if git log -1 | grep 'opnfv-tht-pr:' | grep -o '[0-9]*'; then
+  PR_NUMBER=$(git log -1 | grep 'opnfv-tht-pr:' | grep -o '[0-9]*')
+fi
+
 if [ "$PR_NUMBER" != "" ]; then
   echo "Using pull request $PR_NUMBER from $REPO"
   # Source credentials since we are rate limited to 60/day